Lovett, who played 235 matches for Melbourne from 1986 to 1997 (the 10th most in the club’s history), coached the Scorpions to 14 wins from 18 matches in 2012.
This resulted in Casey finishing on top of the ladder at the end of the home and away season.
But the Scorpions went out in straight sets, losing to Williamstown by 37 points in the semi-finals.
Casey general manager Brian Woodman said Lovett had made an outstanding contribution in his one season with the club.
“We’re disappointed to lose such a fine football person, but we understand his reasons,” Woodman said.
“It’s about him wanting to spend more time with his family and also putting more in to his nursery business. Brett is first and foremost a genuine family man so we can see how he’s come to this decision.
“He’s a tremendous coach and he had an enormous impact with Casey Scorpions. He was highly respected in the way he dealt with players and staff, with a welcoming and sincere approach to all he came across.
“He’s a players’ coach and that’s why we were successful this year. It goes without saying we’re thankful for his contribution and we wish him well with all his future endeavours.”
Woodman said Casey would work to alignment partner Melbourne to identify a suitable replacement.
After playing more than 60 matches with Hawthorn’s reserves in the 1980s, Lovett joined Melbourne and became one of the League’s best half-backs of the late 1980s/early 1990s.
He also played in the centre, and was a strong ball winner.
Lovett represented Victoria on six occasions and came second in Melbourne’s best and fairest in 1988 - the year it played Hawthorn in the grand final.
A creative and brilliant handball exponent, he finished fourth in the 1990 Brownlow Medal.
